#include <iostream>
using namespace std;

const int N = 1e5 + 10;

typedef long long LL;

int n,q;
LL a[N],f[N];

int main(){
	cin >> n >> q;
	for(int i = 1;i <= n;i++){
		cin >> a[i];
		f[i] = f[i - 1] + a[i];
	}
	for(int i = 0;i < q;i++){
		int l,r;
		cin >> l >> r;
		cout << f[r] - f[l - 1] << endl;
	}
	return 0;
}
